Noise Measurement and Effects Flashcards
The ambient noise level may be defined as ________, whereas the peak level is ________
L90, L10
The average sound intensity over a given time, expressed in decibels, is called ________
Leq
On a sound level meter, what does the LAeq value indicate
the average of the cumulative sound energy over a given length of time, that has been converted to a decibel reading.
When the blood supply to the hair cells is diminished, the result may be ________
TTS, dizziness and poor circulation to the hands and feet
What is vasoconstriction?
vasoconstriction refers to reduced blood circulation due to a constriction of the blood vessels in response to noise
What is NIPTS
Noise-induced Permanent Threshold shift - a form of hearing loss
what is AI
Articulation Index - percentage of intelligible words being test
what is SIL
Speech Interference Level - a measure of speech intelligibility in noise
what is STI
Speech Transmission Index - measure of speech intelligibility in noise
A single exposure to a noise around 65dBA may be sufficient to raise sleep level without waking (T or F)
true
Preferred Noise Criterion (PNC) levels for indoor environments specify the ________ levels considered acceptable
ambient noise levels
The Wilson Committee on Noise study of Heathrow Airport devised the ________ measurement system to evaluate aircraft noise
Noise and Number Index - NNI = (Average Peak PNdB) + 15 (log10 N) - 80
What is TNI
Traffic Noise Index -
TNI = 4 . (L10 - L90) + (L90 - 30) (dB)
What is CNEL
Community Noise Equivalent Level - devised in California for evaluating aircraft noise
What is NEF
Noise Exposure Forecast - devised by the FAA for evaluating aircraft noise and land use near airports
